/* eslint-disable @typescript-eslint/no-unused-vars */
// noinspection JSUnusedLocalSymbols

import { Point, type Vector } from '@flatten-js/core';
import type { DrawController } from '../../../src/drawControllers/DrawController';
import { triggerReactUpdate } from '../../../src/state';
import { StateVariable } from '../../../src/helpers/undo-stack';
import { MOUSE_ZOOM_MULTIPLIER } from '../../../src/App.consts';
import { mapNumberRange } from '../../../src/helpers/map-number-range';

/**
 * Screen coordinate system:
 *  0, 0         X
 *    +---------->
 *    |
 *    |
 *    |
 * Y  v
 *
 *
 * World coordinate system:
 * Y  ^
 *    |
 *    |
 *    |
 *    +---------->
 *  0, 0         X
 *
 * To convert between the 2 coordinate systems, you need the screenOffset and screenScale
 */
export class ScreenCanvasDrawController implements DrawController {
	private screenOffset: Point = new Point(0, 0);
	private screenScale = 1;
	private worldMouseLocation: Point;

	constructor(
		private context: CanvasRenderingContext2D | null,
		private canvasSize: Point
	) {
		this.worldMouseLocation = this.targetToWorld(new Point(canvasSize.x / 2, canvasSize.y / 2));
		this.setScreenOffset(new Point(0, 0)); // User expects mathematical coordinates, where y axis goes up, but canvas y axis goes down
	}

	public getCanvasSize() {
		return this.canvasSize;
	}

	public getScreenScale() {
		return this.screenScale;
	}

	public setScreenScale(newScreenScale: number) {
		this.screenScale = newScreenScale;
		triggerReactUpdate(StateVariable.screenZoom);
	}

	public getScreenOffset() {
		return this.screenOffset;
	}

	public setScreenOffset(newScreenOffset: Point) {
		this.screenOffset = newScreenOffset;
		triggerReactUpdate(StateVariable.screenOffset);
	}

	public setScreenMouseLocation(newScreenMouseLocation: Point): void {
		this.worldMouseLocation = this.targetToWorld(newScreenMouseLocation);
		triggerReactUpdate(StateVariable.screenMouseLocation);
	}

	public getWorldMouseLocation(): Point {
		return this.worldMouseLocation;
	}

	public getScreenMouseLocation(): Point {
		return this.worldToTarget(this.worldMouseLocation);
	}

	public panScreen(screenOffsetX: number, screenOffsetY: number) {
		this.screenOffset = new Point(
			this.screenOffset.x - screenOffsetX / this.screenScale,
			this.screenOffset.y - screenOffsetY / this.screenScale
		);
	}

	/**
	 * This function takes the deltaY from the mouse wheel event and zooms the screen in or out
	 * The location of the mouse in world space is preserved
	 * @param deltaY
	 */
	public zoomScreen(deltaY: number) {
		const worldMouseLocationBeforeZoom = this.getWorldMouseLocation();
		const newScreenScale =
			this.getScreenScale() * (1 - MOUSE_ZOOM_MULTIPLIER * (deltaY / Math.abs(deltaY)));
		this.setScreenScale(newScreenScale);

		// now get the location of the cursor in world space again
		// It will have changed because the scale has changed,
		// but we can offset our world now to fix the zoom location in screen space,
		// because we know how much it changed laterally between the two spatial scales.
		const worldMouseLocationAfterZoom = this.getWorldMouseLocation();

		// Adjust the screen offset to maintain the cursor position
		this.screenOffset = new Point(
			this.screenOffset.x + (worldMouseLocationBeforeZoom.x - worldMouseLocationAfterZoom.x),
			this.screenOffset.y + (worldMouseLocationBeforeZoom.y - worldMouseLocationAfterZoom.y)
		);
	}

	/**
	 * Convert coordinates from World Space --> Screen Space
	 */
	public worldToTarget(worldCoordinate: Point): Point {
		return new Point(
			mapNumberRange(
				worldCoordinate.x,
				this.screenOffset.x,
				this.screenOffset.x + this.canvasSize.x / this.screenScale,
				0,
				this.canvasSize.x
			),
			mapNumberRange(
				worldCoordinate.y,
				this.screenOffset.y + this.canvasSize.y / this.screenScale, // inverted since world origin is bottom left and screen  origin is top left
				this.screenOffset.y,
				0,
				this.canvasSize.y
			)
		);
	}

	public worldsToTargets(worldCoordinates: Point[]): Point[] {
		return worldCoordinates.map(this.worldToTarget.bind(this));
	}

	/**
	 * Convert coordinates from Screen Space --> World Space
	 * (0, 0)       (1920, 0)
	 *
	 * (0, 1080)    (1920, 1080)
	 *
	 * convert to
	 *
	 * (0, 1080)    (1920, 1080)
	 *
	 * (0, 0)       (1920, 0)
	 */
	public targetToWorld(screenCoordinate: Point): Point {
		// map the screen coordinate to the world coordinate based on this.getScreenOffset() and the this.getScreenScale()
		return new Point(
			mapNumberRange(
				screenCoordinate.x,
				0,
				this.canvasSize.x,
				this.screenOffset.x,
				this.screenOffset.x + this.canvasSize.x / this.screenScale
			),
			mapNumberRange(
				screenCoordinate.y,
				0,
				this.canvasSize.y,
				this.screenOffset.y,
				this.screenOffset.y + this.canvasSize.y / this.screenScale
			)
		);
	}

	public targetsToWorlds(screenCoordinates: Point[]): Point[] {
		return screenCoordinates.map(this.targetToWorld.bind(this));
	}

	public setLineStyles(
		isHighlighted: boolean,
		isSelected: boolean,
		color: string,
		lineWidth: number,
		dash: number[] = []
	) {}

	public setFillStyles(fillColor: string) {}

	public clear() {}

	/**
	 * Draws a line from startPoint to endPoint and auto converts to screen space first
	 * @param worldStartPoint
	 * @param worldEndPoint
	 */
	public drawLine(worldStartPoint: Point, worldEndPoint: Point): void {}

	/**
	 * Needs to be public to draw UI that is zoom independent, like snap point indicators
	 * @param screenStartPoint
	 * @param screenEndPoint
	 */
	public drawLineScreen(screenStartPoint: Point, screenEndPoint: Point): void {}

	/**
	 * Draw an arc (segment of a circle) or a circle if startAngle = 0 and endAngle = 2PI
	 * @param centerPoint
	 * @param radius
	 * @param startAngle
	 * @param endAngle
	 * @param counterClockWise
	 */
	public drawArc(
		centerPoint: Point,
		radius: number,
		startAngle: number,
		endAngle: number,
		counterClockWise: boolean
	) {}

	public drawArcScreen(
		screenCenterPoint: Point,
		screenRadius: number,
		startAngle: number,
		endAngle: number,
		counterClockWise: boolean
	) {}

	/**
	 * Draw some text at the base location
	 * The direction vector points from the bottom of the first letter towards the bottom of the last letter indicate the rotation of the text   * @param label
	 * @param label
	 * @param basePoint
	 * @param options
	 */
	public drawText(
		label: string,
		basePoint: Point,
		options: Partial<{
			textDirection?: Vector;
			textAlign: 'left' | 'center' | 'right';
			textColor: string;
			fontSize: number;
			fontFamily: string;
		}> = {}
	): void {}

	/**
	 * Draw some text at the base location
	 * The direction vector points from the bottom of the first letter towards the bottom of the last letter indicate the rotation of the text
	 * @param label
	 * @param basePoint
	 * @param options
	 */
	public drawTextScreen(
		label: string,
		basePoint: Point,
		options: Partial<{
			textDirection?: Vector;
			textAlign: 'left' | 'center' | 'right';
			textColor: string;
			fontSize: number;
			fontFamily: string;
		}> = {}
	): void {}

	/**
	 * Draw an image to the canvas using world coordinates
	 * @param imageElement
	 * @param xMin
	 * @param yMin
	 * @param width
	 * @param height
	 * @param angle
	 */
	public drawImage(
		imageElement: HTMLImageElement,
		xMin: number,
		yMin: number,
		width: number,
		height: number,
		angle: number
	): void {}

	public fillRect(xMin: number, yMin: number, width: number, height: number, color: string) {}

	/**
	 * Fill rectangle with color, but interpret the provided coordinates as screen coordinates
	 * @param xMin
	 * @param yMin
	 * @param width
	 * @param height
	 * @param color
	 */
	public fillRectScreen(xMin: number, yMin: number, width: number, height: number, color: string) {}

	/**
	 * Fill polygon with color
	 * @param points
	 */
	public fillPolygon(...points: Point[]) {}
}